Test tray positioning stopper mechanism for automatic handler

ABSTRACT

A mechanism for positioning IC devices to be tested aligned in a test tray of an automatic handler for an IC test system capable of reducing a time for transferring the test tray from a supply area to a test head area which has a plurality of test contactors and from a test head area to a discharge area is disclosed. The mechanism includes a stopper which determines the first stop position of the test tray when said test tray contacts with the outer surface of the test tray and the second stop position of the test tray when said stopper contacts with the end surface of a groove being provided with on its side portion of the test tray to receive and engage with the projection of the stopper. The distance between the adjacent test contactors is adjusted to be equal to two times or integer multiple of the distance between the adjacent IC devices to be tested aligned in the test tray and the distance between the first position and the second position is adjusted to be equal to the distance between the adjacent IC devices to be tested so that minimizing the index time for transferring the test tray becomes possible.

This application is a divisional of U.S. patent application Ser. No.08/410,821, filed Mar. 27, 1995 now U.S. Pat. No. 5,625,287.

FIELD OF THE INVENTION

The present invention relates to an automatic handler for an IC testsystem that transfers IC devices to be tested, from a supply area to atest head area and then to a discharge area, which is capable ofminimizing a time for transferring test trays having the IC devicesthereon and replacing the test trays, and more particularly, a test traypositioning stopper mechanism for automatic handler to increaseflexibility and a choice of a number of IC devices to be testedsimultaneously.

BACKGROUND OF THE INVENTION

In general, an IC test system performs an IC device test by electricallycontacting IC devices to be tested with test contactors in pinelectronics or pin cards provided in a test head area to supply testsignals to the IC devices and receive the resulted outputs from the ICdevices. The resulted signals are compared with expected signals todetermine whether the outputs from the IC devices are acceptable or not.

Hence, an automatic handler transfers IC devices to be tested from asupply area to a test head area. After the test, IC devices that havebeen tested are transferred from the test head area to a discharge areaand are sorted according to the test results. During these timesrequired for transferring the IC devices, the test cannot be performedsince IC devices to be tested cannot determine their position withrespect to contactors in the test head and thus they cannot beelectrically contacted. Reducing this transfer time, i.e., an indextime, is desirable since the index time is useless for the IC devicetesting. Hence, there is a need to minimize the index time in anautomatic handler.

FIG. 7 shows a conventional automatic handler for an IC test system. Asshown, test trays 20 are used as means of transferring IC devices 16 tobe tested in the IC test system. A plurality of carrier modules 30 aremaintained in a floating state in each test tray 20. An IC device 16 ismounted on each-carrier module 30. The test trays 20 having the ICdevices 16 are arranged at the supply area SU. IC devices 16 are thentransferred to the test head area TH while being maintained on the testtray 20. At the test head area TH, the test tray 20 is carried on a beltconveyer 18 by a driving power of a motor 17 until the test tray isstopped by a projection of a stopper 11.

At the test head area TH, the test tray 20 is positioned and fixed bythe stopper 11. Then, the IC devices 16 are pushed downward, forexample, for the electric connection with the test contactors of the pinelectronics (not shown) provided at the test head in the IC test system.The IC devices 16 keep electronic contact with the pin electronics inthe IC test system during the- testing. Recently, a plurality of testhead areas are provided for performing simultaneous testing of ICdevices mounted on a plurality of test trays. The test tray 20 is thentransferred to the discharge area DI where the IC devices 16 areclassified depending on the test results.

FIG. 8 is a schematic diagram showing an example of test process in aconventional automatic handler. In the example shown in FIG. 8A, thereare four (4) IC devices 16 seated in the test tray 20. In recent years,smaller devices are widely used and thus a larger number of IC devices,such as eight (8) IC devices can be arranged in the test tray 20according to the actual density of IC devices as shown in FIG. 8A.However, a distance between the IC devices is limited to x in FIG. 8Abecause of the limitation in a packaging density such as in thecontactors of the pin electronics in the test heads. Namely, since thetest contactors in the pin electronics of the IC test system consist ofmechanical and electronics parts and thus require a certain size andspace which determines the minimum distance x.

Hence, in the example of FIG. 8A, four IC devices 16 are arranged in alength L of the test tray 20. The test tray 20 is shifted from thesupply area SU to the test head area TH. After the test tray 20 istransferred to the stopper 11 in the test head area TH, each IC device16 is electrically contacted by the pin electronics (not shown) as shownin FIG. 8B and the test is initiated. After the test, the projection ofthe stopper 11 withdraws so that the test tray 20 transfers to thedischarge area DI. As a result, the test for the IC devices in the nexttest tray can be ready. In the above procedure, when the transfer speedof the test tray 20 is s, the index time per device is expressed

    t1=L/4s

Since the IC test system of FIG. 8 has one test head, the index time perdevice per automatic handler is also

    t01=L/4s.

FIG. 9 is a schematic diagram showing an example of test process of ICdevice testing in another conventional automatic handler. In the exampleof FIG. 9, the IC test system includes two test heads TH1 and TH2. Asshown in FIG. 9, eight (8) IC devices 16 are arranged in the test tray20. The spacings between the IC devices to be tested are y where it isassumed that x/2<y<x. The IC devices 16 to be tested are arranged in theway that the spacing y between the IC devices 16 to be tested areminimized to the limit of the packaging density of the IC devices 16 inthe length L of the test tray 20. In contrast, as discussed above withreference to FIG. 8, the distance x is determined by the density of thetest contactors in the pin electronics which is larger than that of theIC devices.

As shown in FIG. 9A, the test tray 20 is transferred from the supplyarea SU to the first test head TH1 by the transfer system such as shownin FIG. 7. The position of the test tray is determined by the stopper11₁ provided at the first test head TH1 by the transfer system. Then,the IC devices 16 on the test tray are electrically contacted with thepin electronics in the test head area so that the test is initiated.Since there is a limitation in the density such as in the pinelectronics or pin cards in the test heads, and thus the plurality oftest contactors in the pin electronics have a greater spacing x than thespacing y of the IC devices 16 to be tested, not all IC devices 16 inthe test tray 20 can be simultaneously tested. Therefore, for example,at the first test head TH1, only the IC devices 16 of odd lines in thetest tray 20 are electrically contacted and tested. This is shown inFIG. 9B by the shades of the corresponding IC devices 16 in the testtray 20.

After finishing the test for the IC devices 16 in the odd lines, theprojection of the stopper 11₁ at the test head TH1 is detracted and thetest tray 20 is transferred to the second test head TH2 as shown in FIG.9C. The test tray 20 is positioned accurately at the second test headTH2 by the stopper 11₂. At the test head area TH2, this time, only theIC devices 16 of even lines in the test tray 20 are electricallycontacted by the pin electronics in the second test head TH2 as shown bythe shaded lines in FIG. 9C.

Since there are two (2) test heads TH1 and TH2 are provided in thisexample and both test heads can perform the test simultaneously, it ispossible for the second test head TH2 to test the IC devices in the evenlines in the test tray 20 while the first test head TH1 simultaneouslytests IC devices in the odd lines in the next test tray. Thus, all eight(8) IC devices 16 to be tested in the test tray 20 can be tested in themanner described above by allocating the IC devices to the first testhead TH1 and the second test head TH2. After the test, the projection ofthe stopper 11₂ at the second test head TH2 pulls back, and the testtray 20 is transferred to the discharge area DI as shown in FIG. 9D.

In this situation, when the transfer speed of the test tray 29 isexpressed as s, the index time per device in the simultaneous testingperformed continuously as above is:

    t2=L/8s.

The index time per device per automatic handler is:

    t02=L/4s.

As shown above, the index time per automatic handler needs L/4s foreither t01 or t02 cases. Hence, whichever conventional means of FIGS. 7or 9 are performed, the time length for the transfer of the test tray islimited to the index time above and cannot be decreased any further.

SUMMARY OF THE INVENTION

Therefore, it is an object of the present invention to provide anautomatic handler for an IC test system which is capable of minimizingthe index time required for transferring the test trays having ICdevices to be tested by uniquely arranging a plurality of stoppers forpositioning the test trays.

It is another object of the present invention to provide an automatichandler for an IC test system which is capable of minimizing the indextime for transferring the test trays by providing a plurality ofstoppers corresponding to a single test head of the IC test system todetermine a plurality of positions in the test head area.

It is another object of the present invention to provide an automatichandler which is capable of increasing the number of test positions forthe test tray by providing a groove on the test tray which receives andengages with projections of the stoppers.

It is a further object of the present invention to provide an automatichandler for an IC test system which is capable of minimizing the indextime without increasing mechanical parts or spacing in the handler.

According to the first aspect of the present invention, IC devices to betested are arranged in the length of the test tray to a limit of theirdensity. After being transferred to a test head area by a transfersystem, the test tray is positioned by a first positioning stopper. TheIC devices in a predetermined line in the test tray are electricallycontacted with contactors in pin electronics of the test head area andthe IC test is performed. At this point, only the IC devices of oddlines, for example, are electrically contacted and tested at this firststep since the spacing of the contactors in the test head is larger thanthat of the IC devices in the test tray.

After the test for the IC devices in the odd lines, a projection of thefirst positioning stopper is retracted so that the test tray istransferred to the next position where it is positioned by a secondstopper. At this second step, only IC devices of even lines in the testtray are electrically contacted with the contactors in the pinelectronics to proceed the IC test. Thus, when the test tray transfersfrom the first step to the second step, the test tray transfers thedistance D which is the distance between the first stopper and thesecond stopper. This distance D is also identical to the spacing betweenthe IC devices in the test tray.

After the test, a projection of the second stopper at the test head areais retracted and the test tray advances to a discharge area. In thiscase, the transfer distance of the test tray is (L-D). Thus, thetransfer distance of the test tray is reduced compared to theconventional arrangement, which contributes to a reduction of the indextime.

According to the second aspect of the present invention, a groove isprovided on the test tray to receive the positioning stoppers therein.The groove has a predetermined length including an end surface thedistance of which is an integer multiple, for example, twice as long asthe distance between the positioning stoppers.

There can be several grooves on the test tray and at least one stopperis needed. Consequently, the number of possible test positions for thetest tray is increased to the number of grooves multiplied by the numberof stoppers.

Thus, by setting the distance between a flat surface in the front of thetest tray and the end surface of the groove as twice as long as thedistances between two stoppers, the total test positions for the testbecomes four.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing the second embodiment of theautomatic handler in accordance with the present invention.

FIG. 2 is a schematic view of an automatic handler for explaining asituation where test trays stop at four (4) positions in a test headarea in the second embodiment of the present invention of FIG. 1.

FIG. 3 is a schematic view of the first embodiment of the automatichandler in accordance with the present invention showing a situationwhere test trays stop at two (2) positions in a test head area.

FIG. 4 is a schematic diagram showing a test procedure of IC devices inaccordance with the automatic handler of the first embodiment of FIG. 3.

FIG. 5 is a plain view showing the first embodiment of the presentinvention.

FIG. 6 is a perspective view for explaining the relationship between thetest tray and the positioning stopper in the first embodiment of thepresent invention.

FIG. 7 is a diagram showing an example of conventional automatic handlerfor an IC test system.

FIG. 8 is a schematic view showing a test process for IC devices in theconventional automatic handler of FIG. 7.

FIG. 9 is a schematic view showing a test process for IC devices inanother example of conventional automatic handler.

DETAILED DESCRIPTION OF THE INVENTION

Preferred embodiments of the present invention will be described withreference to the drawings. FIG. 5 shows the first embodiment of thepresent invention. FIG. 5 is a plan view showing an automatic handlercorresponding to a test head area TH of an IC test system. The test tray20 having the IC devices 16 to be tested is placed on the belt conveyer18 which is driven by the motor 17 as in the same manner shown in FIG.7. In FIG. 5, in addition to the conventional stopper 11, the secondstopper 12 is also provided in the test head TH along a moving directionof the test tray 20. The distance D between the second stopper 12 andthe first stopper 11 is adjusted to be equal to the distance y betweenthe adjacent IC devices 16 to be tested in the test tray 20. The ICdevices 16 to be tested in the test tray 20 is arranged in a mannerdiscussed with respect to FIG. 9 where the spacing y between the ICdevices is decreased to the minimum possible value. An operation ofextension and withdrawal of the projection in each stopper is controlledindependently.

FIG. 4 is a schematic diagram showing a test process of the IC devices16 to be tested according to the automatic handler of the presentinvention. In the example of FIG. 4, eight (8) IC devices 16 to betested are arranged in the test tray 20. Namely, the IC devices 16 to betested are aligned in the test tray 20 such that the spacing between theadjacent devices is reduced to the minimum in terms of packaging densityof the IC devices 16 to be tested. Thus, the IC devices 16 to be testedare aligned with the spacing y in the test tray 20 whose length is L.

The test tray 20 is moved from the supply area SU to the test head areaTH until it is stopped by the stopper 11 provided in the test head areaTH as shown in FIG. 4A. Then the test tray 20 is pressed downward, forexample, for accomplishing the electrical contact between the testcontactors in the pin electronics of the IC test system and the ICdevices 16 to be tested as shown in FIG. 4B. At this time, only the ICdevices of the odd lines in the test tray 20 are electrically connectedand tested as shown by the shaded lines of FIG. 4B. This is because thetest contactors in the pin electronics in the test head TH have theminimum distance x which is different from the minimum distance y of ICdevices in the test tray 20. Usually, the distance x between theadjacent test contactors is greater than the distance y between theadjacent IC devices 16 aligned in the test tray 20. Therefore, in thisexample, the distance x in the test head is adjusted to be x=2y to thatthe IC devices in the every other lines in the test tray 20 can beelectrically connected with the test head.

After finishing the test for the IC devices in the odd lines, theprotrusion of the first stopper 11 is pulled in and the test tray 20 istransferred to the right hand side until it is stopped by the secondstopper 12 as shown in FIG. 4C. The test tray 20 is then fixed by theprojection of the second stopper 12 in the appropriate position in thetest head area TH. As stated above, the spacing between the firststopper 11 and the second stopper 12 is D which is the same as distancey between the IC devices 16 in the test trays 20. Thus, when the testtray 20 transfers from the first step (FIG. 4B) to the second step (FIG.4C), the IC devices in the even lines are positioned to contact with thecontactors in the test head TH.

At this position, the IC devices in the even lines in the test tray 20are electrically connected with the test contactors of the pinelectronics in the IC test system and tested thereby. Therefore, in thefirst position which is determined by the first stopper 11, the ICdevices 16 in the odd lines in the test tray 20 are tested and in thesecond position which is determined by the second stopper 12, the ICdevices 16 in the even lines in the test tray 20 are tested. As aresult, all of the eight (8) IC devices in the test tray 20 can betested after the process of FIG. 4C. Then, the projection of the secondstopper 12 is withdrawn and the test tray 20 is transferred to thedischarge area DI.

In this process, the transfer distance of the test tray 20 between thesecond position and the discharge area DI is (L-D) as shown in FIG. 4D.When the transfer speed of the test tray 20 is s, the index time perdevice is:

    t3=(D/s+(L-D)/s)/8=L/8s

The index time per device per automatic handler is

    t03=L/8s

Hence, the index time in this example can be reduced to a half of thatin the conventional automatic handler of FIGS. 7 or 9 in which the indextime is L/4s.

In the above example, the IC test is performed in two steps, i.e., bydividing the IC devices in the odd lines and in the even lines in thetest tray 20. However, based on the inventive features of the presentinvention, the test can be divided into three steps when even smaller ICdevices to be tested are arranged in the test tray. In such a situation,the number of stoppers to be provided will be increased to three each ofwhich is apart from one another by the distance the same as that of theIC devices in the test tray.

Further, the number of steps or the stoppers can be increasedarbitrarily according to the relationship between the spacing in the ICdevices in the tray and the spacing of the pin electronics in the testhead. Even if the number of stoppers and thus the steps for testing theIC devices to be tested is altered, the index time can be increased inthe same manner as describe in the foregoing. The only limitation inincreasing the number of the stoppers is that the stoppers have to bealigned in the direction to which the test tray is transferred.

FIG. 6 shows an example of the test tray 20 and the positioning stoppers11 and 12. In this example, the stopper 11 and the stopper 12 aredistanced by a pitch D and are arranged on a stopper body 13. Theprojections P₁₁ and P₁₂ on the end of the stoppers 11 and 12,respectively, are driven independently from each other.

The test tray 20 is provided with, for example, 64 carrier modules 30 sothat 64 IC devices to be tested can be loaded in the seats of thecarrier modules 30. The test tray 20 has a flat surface 14 and istransferred to the moving direction Q in FIG. 6. In the test area, theflat surface 14 meets with the projection P₁₁ of the stopper 11 or theprojection P₁₂ of the stopper 12 so that the appropriate positions ofthe IC devices to be tested is determined with respect to the pinelectronics in the test head.

Thus, the test tray 20 can be stopped at two positions distanced by thepitch D on the test head area. The first positioning can be accomplishedwhen the projection P₁₁ of the stopper 11 touches the flat surface 14.Then, after testing the predetermined lines of IC devices on the testtray 20, the projection P₁₁ is retracted in the stopper 11 so that thetest tray 20 can further advances to the direction Q. The flat surface14 of the test tray 20 then meets with the projection P₁₂ of the stopper12, which determined the second position of the test tray 20 on the testhead area.

FIG. 3 shows an arrangement of an automatic handler for use with an ICtest system having two test heads (test chambers) TH1 and TH2 fortesting the IC devices. In this arrangement, the automatic handlerincludes stoppers 11₁ and 12₁ for the first test head TH1, and stoppers11₂ and 12₂ for the second test head TH2. In each pair of the stoppers,one stopper is separated by a distance D from the other. A pair ofplural position sensors 15₁ and 15₂ are also provided in each test headfor monitoring the movement of the test trays 20. In this example,although not shown, the test contactors of the pin electronics in eachof the test heads TH1 and TH2 have a spacing with respect to theadjacent contactors by a distance which is four times larger than thedistance D between the IC devices 16.

Thus, in the first test head TH1, four lines (A, C, A, C) of IC devicesin the test tray 20 are first tested at the position determined by thestopper 11₁ as shown in FIG. 3a. Then, also in the test head TH1,another four lines (B, D, B, D) of IC devices in the test tray 20 aretested at the position determined by the stopper 12₁ as shown in FIG.3b, which is shifted by the distance D from the previous position.Namely, in this example, 32 IC devices are tested in the first test headTH1.

The test tray 20 is then transferred to the second test head TH2 asshown in FIGS. 3c and 3d. In the second test head TH2, four lines (E, G,E, G) of IC devices in the test tray 20 are first tested at the positiondetermined by the stopper 11₂ as shown in FIG. 3c. Then, also in thesecond test head TH2, another four lines (F, H, F, H) of IC devices inthe test tray 20 are tested at the position determined by the stopper12₂ as shown in FIG. 3d, which is shifted by the distance D from theprevious position. Thus, in this example, a total of 64 IC devices aretested in the first and second test heads TH1 and TH2.

In the example of FIGS. 3 or 5, when more devices are attempted to betested in each test head or when the spacing difference between the ICdevices to be tested and the pin electronics is greater than the exampleof FIG. 3, the IC test can be carried out in a similar manner byincreasing the number of stop positions in each test head. Such anincrease of stop positions is possible by providing the correspondingnumber of stoppers in the direction where the test tray advances.However, the following problem occurs in such modification. Namely, thenumber of stop positions may be limited since the number of stoppershave to be increased accordingly. One of the reasons is that theincrease in the number of stoppers causes an increase of correspondingmechanical parts and drive mechanism which will increase the overallsize of the automatic handler.

FIG. 1 shows the second embodiment of the present invention which isable to increase the number of stop positions without increasing thenumber of stoppers. FIG. 1 shows an example in which four (4) stoppositions are established for each test head. In this example, thepositioning stoppers 11 and 12 are the same as the one used in the firstembodiment and may be mounted on the stopper body 13 as discussed withreference to FIG. 6. The major difference between the first embodimentand the second embodiment is that, in this embodiment, it is providedwith a groove 21 on the test tray 20 to receive the stoppers 11 and 12therein. The groove 21 is positioned on the side of the test tray 20which is in parallel to the tray moving direction. The end surface 22 ofthe groove 21 has an accurate distance D from the flat surface 14 of thetest tray 20, which is, for example, two time as long as the distancebetween D the stoppers 11 and 12.

With further reference to FIG. 1, the operation of positioning the testtray at the 4 positions is explained. In the following, the state wherethe projections of the stopper 11 or 12 expands to stop the test tray 20is regarded as ON, while the state where the projection of the stopper11 or the stopper 12 retracts to allow the test tray 20 go forward isregarded as OFF.

Position A

The stopper 11 and the stopper 12 are both turned ON as shown in FIG.1a. The projection of the stopper 11 contacts the flat surface 14 of thetest tray so as to fix the position A of the test tray 20.

Position B

The projection of the stopper 11 is turned OFF at the position A so thatthe test tray 20 advances in the right hand direction until the flatsurface 14 contacts with the projection of the stopper 12. The test tray20 then stops at the position B which is a distance D from the positionA.

Position C

At the position B, the stopper 11 is turned ON while the stopper 12 isturned OFF. Thus, the projection of the stopper 11 is in the groove 21of the test tray 20. The test tray 20 moves in the transfer directionuntil the end surface 22 of the groove 21 meets with the projection ofthe stopper 11. The test tray 20 then stops at the position C which is adistance D from the position B.

Position D

At the position C, the stopper 12 is turned ON while the stopper 11 isturned OFF. Thus, the projection of the stopper 12 is in the groove 21of the test tray 20 while the projection of the stopper 11 withdrawsfrom the groove 21. The test tray 20 moves in the transfer directionuntil the end surface 22 of the groove 21 contacts the projection of thestopper 12. The test tray 20 then stops at the position D which is adistance D from the position C.

Therefore, in the example of FIG. 1, the four test positions each ofwhich is apart from the other by the distance D are realized by the twostoppers 11 and 12. The IC devices in the corresponding positions in thetest tray 20 will be tested in each position. After the test, thestopper 11 and the stopper 12 are turned OFF in order to transfer thetest tray 20 to the next test head or the discharge area of theautomatic handler.

FIG. 2 shows an example of automatic handler where the stoppers and thegroove in test tray shown in FIG. 1 are used in the IC test systemhaving two test heads (test chambers) TH1 and TH2 for testing the ICdevices. In this arrangement, similar to the example of FIG. 3, theautomatic handler includes stoppers 11₁ and 12₁ for the first test headTH1 and stoppers 11₂ and 12₂ for the second test head TH2. In each pairof the stoppers, one stopper is separated by a distance D from theother. The IC devices to be tested in the test tray 20 are also apartfrom one another by the distance D.

The test tray 20 is provided with a groove 21 and a end surface 22 ofthe groove as shown in FIG. 1. The end surface is distanced from theflat surface 14 of the test tray 20 by 2D. A pair of plural positionsensors 15₁ and 15₂ are also provided in each test head for monitoringthe movement of the test trays 20. Although not shown, the pinelectronics in each of the test heads TH1 and TH2 has a spacing withrespect to the adjacent pin electronics by a distance which is eighttimes larger than the distance D between the IC devices.

Thus, in the first test head TH1, the IC devices in the two lines (A, A)in the test tray 20 are first tested at the position A determined by thestopper 11₁ as shown in FIG. 2a. Then, also in the test head TH1,another two lines (B, B) of IC devices are tested at the position Bdetermined by the stopper 12₁ as shown in FIG. 2b, which is shifted bythe distance D from the previous position. Further, the IC devices intwo lines (C, C) are tested at the position C which is determined by thestopper 11₁ and the groove 21. Moreover, the IC devices in two lines (D,d) are tested at the position D which is determined by the stopper 11₂and the groove 21. Namely, in this example, 32 IC devices are tested inthe first test head TH1.

The test tray 20 is then transferred to the second test head TH2 whereinthe IC devices in each two lines in the test tray 20 are tested in thesame manner in the first test head TH1 as described above as shown inFIGS. 2e-2h. Thus, in the test head TH2, the test tray 20 is positionedin the four positions by the pair of stoppers 12₁ and 12₂ in eachposition of which the IC devices of each two lines in the test tray aretested. Therefore, in this arrangement of FIG. 2, a total of 64 ICdevices are tested in the first and second test heads TH1 and TH2.

In the above example, it is disclosed that a single groove is providedon the test tray to increase the number of test positions. However, thepresent invention can be applied to a situation where two or moregrooves are provided on the test tray 20 to further increase the numberof test positions without increasing the number of stoppers. Namely, thenumber of positions for the test tray 20 can be increased by the numbersof grooves multiplied by the numbers of stoppers.

The distance E that is from the flat surface 14 of the test tray 20 tothe end surface 22 of the groove 21 in FIG. 1 can be made twice as longas D which is the distance between the stopper 11 and the stopper 12.Then, the test tray 20 can stop at each position spaced by the distanceD. Also, the test tray 20 can be stopped at different intervals bychanging the distances D and E.

According to the present invention, when the first embodiment isperformed, the following advantages are obtained. The index time isdecreased to a half of the conventional ones since an automatic handlerfor an IC test system is comprised of a plurality of stoppers 11 and 12provided along the moving direction of the test tray 20 in a test headarea. Thus, the present invention provides an automatic handler for anIC test device which is able to reducing the index time required whendevices to be tested are transferred from the supply area to the testhead area or from the test head area to the discharge area in the ICtest system.

When the second embodiment is implemented, the number of test positionsfor the test tray per test head can be increased without increasingmechanical components or spaces in the automatic handler. Consequently,IC devices to be tested at one position can be reduced and the number ofstops can be the same as conventional ones. Hence, an automatic handlerof the present invention allows flexibility of IC test where the numberof devices to be tested at a time is increased and freely selectable.

We claim:
 1. A mechanism for positioning IC devices to be tested alignedin an automatic handler for an IC test system which transfers the ICdevices from a supply area to a test head area which has a plurality oftest contactors and further transfers the tested IC devices from saidtest head area to a discharge area, comprising:a test tray for carryingsaid IC devices to be tested and transferring said IC devices from saidsupply area to said test head area and then to said discharge area by atransfer system, said test tray being provided with a flat outer surfaceat one end thereof and a groove of a predetermined length on a surfaceof said test tray other than said flat outer surface, said IC devices tobe tested being aligned in said test tray with a distance between twoadjacent IC devices which is shorter than a distance between twoadjacent test contactors in said test area; and a stopper whichdetermines a first stop position of said test tray when said stoppercontacts with said flat outer surface of said test tray and a secondstop position of said test tray when said stopper contacts with an endsurface of said groove; wherein said distance between said testcontactors is adjusted to be equal to or integer multiple of saiddistance between said IC devices to be tested aligned in said test tray,and a distance between said first stop position and said second stopposition of said test tray is adjusted to be equal to said distancebetween said IC devices aligned in said test tray.
 2. A mechanism forpositioning a test tray as defined in claim 1, wherein:said stopper iscomprised of two stopper mechanisms independently operable from oneanother, said two stopper mechanisms being separated by a distance equalto said distance of said IC devices in said test tray; said distancebetween said flat outer surface of said test tray and said end surfaceof said groove is equal to two times of said distance between said twostopper mechanisms; whereby said test tray is adjusted in four positionseach of which is apart by said distance between said two stoppermechanisms.
 3. A mechanism for positioning a test tray as defined inclaim 2, wherein said stopper is comprised of three or more stoppermechanisms, and said test tray includes two or more grooves, therebyrealizes more than five test positions for said IC devices to be tested.